[azure 4.13][PATCH 06/19] Revert "UBUNTU: SAUCE: vmbus: dynamically enqueue/dequeue a channel on vmbus_open/close"

[Marcelo Henrique Cerri]

From: Dexuan Cui <decui at microsoft.com>

BugLink: http://bugs.launchpad.net/bugs/1736283

This reverts commit 733807e8a430347ecb71d94eeb2e4050cefe0dd3.

Signed-off-by: Dexuan Cui <decui at microsoft.com>
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri at canonical.com>
---
 drivers/hv/channel.c      | 12 +++-------
 drivers/hv/channel_mgmt.c | 60 +++++++++++++++++++++--------------------------
 include/linux/hyperv.h    |  3 ---
 3 files changed, 30 insertions(+), 45 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index dfeca41f8413..a76180bcb9f7 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -197,8 +197,6 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 		goto error_free_gpadl;
 	}
 
-	hv_percpu_channel_enq(newchannel);
-
 	ret = vmbus_post_msg(open_msg,
 			     sizeof(struct vmbus_channel_open_channel), true);
 
@@ -211,25 +209,23 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 
 	if (ret != 0) {
 		err = ret;
-		goto error_deq_channel;
+		goto error_free_gpadl;
 	}
 
 	if (newchannel->rescind) {
 		err = -ENODEV;
-		goto error_deq_channel;
+		goto error_free_gpadl;
 	}
 
 	if (open_info->response.open_result.status) {
 		err = -EAGAIN;
-		goto error_deq_channel;
+		goto error_free_gpadl;
 	}
 
 	newchannel->state = CHANNEL_OPENED_STATE;
 	kfree(open_info);
 	return 0;
 
-error_deq_channel:
-	hv_percpu_channel_deq(newchannel);
 error_free_gpadl:
 	vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
 	kfree(open_info);
@@ -584,8 +580,6 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
 		goto out;
 	}
 
-	hv_percpu_channel_deq(channel);
-
 	channel->state = CHANNEL_OPEN_STATE;
 	channel->sc_creation_callback = NULL;
 	/* Stop callback and cancel the timer asap */
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 92c9cd9b6c26..4f64561eac7a 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -362,22 +362,6 @@ static void percpu_channel_enq(void *arg)
 	list_add_tail_rcu(&channel->percpu_list, &hv_cpu->chan_list);
 }
 
-void hv_percpu_channel_enq(struct vmbus_channel *channel)
-{
-	unsigned long flags;
-
-	if (channel->target_cpu != get_cpu())
-		smp_call_function_single(channel->target_cpu,
-					 percpu_channel_enq, channel, true);
-	else {
-		local_irq_save(flags);
-		percpu_channel_enq(channel);
-		local_irq_restore(flags);
-	}
-
-	put_cpu();
-}
-
 static void percpu_channel_deq(void *arg)
 {
 	struct vmbus_channel *channel = arg;
@@ -385,23 +369,6 @@ static void percpu_channel_deq(void *arg)
 	list_del_rcu(&channel->percpu_list);
 }
 
-void hv_percpu_channel_deq(struct vmbus_channel *channel)
-{
-	unsigned long flags;
-
-	if (channel->target_cpu != get_cpu())
-		smp_call_function_single(channel->target_cpu,
-					 percpu_channel_deq, channel, true);
-	else {
-		local_irq_save(flags);
-		percpu_channel_deq(channel);
-		local_irq_restore(flags);
-	}
-
-	put_cpu();
-}
-
-
 static void vmbus_release_relid(u32 relid)
 {
 	struct vmbus_channel_relid_released msg;
@@ -428,6 +395,14 @@ void hv_process_channel_removal(u32 relid)
 		return;
 
 	BUG_ON(!channel->rescind);
+	if (channel->target_cpu != get_cpu()) {
+		put_cpu();
+		smp_call_function_single(channel->target_cpu,
+					 percpu_channel_deq, channel, true);
+	} else {
+		percpu_channel_deq(channel);
+		put_cpu();
+	}
 
 	if (channel->primary_channel == NULL) {
 		list_del(&channel->listentry);
@@ -527,6 +502,16 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
 
 	init_vp_index(newchannel, dev_type);
 
+	if (newchannel->target_cpu != get_cpu()) {
+		put_cpu();
+		smp_call_function_single(newchannel->target_cpu,
+					 percpu_channel_enq,
+					 newchannel, true);
+	} else {
+		percpu_channel_enq(newchannel);
+		put_cpu();
+	}
+
 	/*
 	 * This state is used to indicate a successful open
 	 * so that when we do close the channel normally, we
@@ -590,6 +575,15 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
 	list_del(&newchannel->listentry);
 	mutex_unlock(&vmbus_connection.channel_mutex);
 
+	if (newchannel->target_cpu != get_cpu()) {
+		put_cpu();
+		smp_call_function_single(newchannel->target_cpu,
+					 percpu_channel_deq, newchannel, true);
+	} else {
+		percpu_channel_deq(newchannel);
+		put_cpu();
+	}
+
 	vmbus_release_relid(newchannel->offermsg.child_relid);
 
 err_free_chan:
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 2d8b937bbd90..f9088f52273d 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1434,9 +1434,6 @@ extern bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, u8 *buf,
 				const int *srv_version, int srv_vercnt,
 				int *nego_fw_version, int *nego_srv_version);
 
-void hv_percpu_channel_enq(struct vmbus_channel *channel);
-void hv_percpu_channel_deq(struct vmbus_channel *channel);
-
 void hv_process_channel_removal(u32 relid);
 
 void vmbus_setevent(struct vmbus_channel *channel);
-- 
2.7.4